April 30, 2009

Potential depression drug target is found

U.S. scientists say they have identified an acid-sensitive brain protein that might become a new drug target for the treatment of depression

Investigators at the University of Iowa led by researcher Matthew Coryell and Dr. John Wemmie said they determined disrupting acid-sensitive ion channel-1a produces antidepressant-like effects in mice. They said that finding might one day benefit people who don't respond to traditional antidepressants or who can't tolerate their side effects.

Although animal models can't reproduce all the symptoms of human depression, the researchers said several behavioral tests show rodents are sensitive to antidepressant treatment, suggesting they address important aspects of the disease.

For example, chronically stressed mice lose their normal preference for sugary drinks and mice repeatedly placed in a pool tend to give up and float rather than swim in the hopes of escaping. Those mouse behaviors, the researchers said, are thought to reflect loss of interest in pleasurable activities and hopelessness or despair. But traditional antidepressants are able to restore the mouse preference for sweet treats and reduce the amount of time they float rather than swim.

The researchers said they determined the new treatment works through a different biological pathway than traditional antidepressants, suggesting it may benefit people who do not respond to traditional therapies.

The research appears in the Journal of Neuroscience.